It is well known that the safety of motorcyclists is an ongoing concern. Over the years a large number of products, created for reducing the risk of injuries in an accident, have been introduced in the market.
For reducing the risk of injuries, the motorcyclists usually wear protective garments made with materials resistant to abrasion, like leather or synthetic material. Such garments might be provided in some areas, for example in the region of the shoulders, the knees, and the back, with rigid or semi-rigid protection elements designed for limiting impact forces.
Recently the protection offered by said protective garments has been improved by integrating inflatable protective devices into the structure of the abrasion resistant garment.
Such inflatable protective devices are designed for being inflated as soon as a crash situation is detected so as to offer an additional protection to the motorcyclist.
Currently two methods are mainly used for detecting a crash situation so as to quickly inflate the inflatable protective device integrated in the garment.
The first method is disclosed in PCT patent application WO 02/054895 wherein an inflatable protective device, triggered by means of a cable that connects the garment worn by the user with the motorcycle, is disclosed. Should the motorcyclist be thrown from or fall off of the motorcycle the resulting force applied to the triggering cable is transmitted to the inflating cartridge of the protective device for releasing the gas that inflates the protective bladders.
The second method is disclosed in U.S. Pat. No. 8,348,304. Such US patent shows an airbag jacket activating system including a motorcycle and an airbag jacket worn by the rider of the motorcycle.
The system comprises an ECU (electronic control unit), mounted on the rear part of the motorcycle, suitable for controlling the inflator of the inflatable air chambers provided on the jacket.
The ECU, on the basis of the acceleration detected by an acceleration sensor mounted on the motorcycle, is able to judge whether the airbag jacket worn by the user should be deployed. Subsequently, the ECU transmits an ignition signal to a transceiver mounted on the airbag jacket so as to activate the activation device of the inflator.
A third method has been recently proposed. According to this method, that is disclosed in the PCT patent application WO 2014/001189, the garment is provided with a triggering device mounted directly on the garment. The triggering device does not require the provision of a triggering cable nor require the provision of electronic sensors on the motorcycle. Advantageously, in this case, the freedom of movement of the motorcyclist is not hindered by the presence of a triggering cable. At the same time, the motorcyclist does not need to install any equipment on his motorcycle beforehand, making the protective system cheaper and simpler.
All of the above patents/patent applications do not face the problem of how the corresponding systems should be integrated when there are two people travelling on the motorcycle.
The first and third method above disclosed assume that the rider and passenger will purchase and wear duplicate systems. This means that in the event of an accident the person who is closest to the impact will have his garment inflated first. For example if the motorcycle hits a car in front the rider airbag will inflated first, and passenger second. However if the motorcycle is hit from behind by a car then the passenger airbag will be inflated first and the rider airbag will be inflated second.
The second method above disclosed in theory might envisage the use of an ECU suitable for activating, with only one signal, at the same time the garment of the rider and the garment of the passenger. However, the drawback of this method is that the acceleration sensors are positioned on the motorcycle. Therefore, the garments of the rider and passenger are not stand-alone devices suitable for being used in cooperation with different motorcycle.
Moreover this method discloses the use of a single acceleration sensor positioned on the rear portion of the motorcycle. A single location of the acceleration sensor on the motorcycle could give a delayed deployment of the protection system if the motorcycle is hit on the front portion.
Furthermore, since passenger and rider are not rigidly engaged on the motorcycle, it is not assured that the acceleration detected by sensor mounted on the motorcycle is sufficiently indicative of the necessity to inflate the airbag in the protective garment, i.e. that the true acceleration of the passenger or the rider is dangerous.